Construction Of Flexible Microfluidics And Interface Design For Antifouling Research

Microfluidics,owing to its advantages of small sample volume,high sensitivity,large specific surface area,low cost,and shortened analysis time,provides a wide range of potential applications.Especially with the advent of the 5G era,microscale fluidic devices will become the new technology for smart life applications in the future.However,the fabrication of flexible microchannels has always been a tough task using conventional manufacturing technologies because every application for flexible microchannels is restricted by their complex fabrication process and limited material selection.At the same time,since its large specific surface area,the application of microchannel is plagued with fouling problems,which is a daunting issue and restricts practical applications of microfluidic channels.Based on the above complex preparation and microfluidic fouling problems,this thesis will be divided into six chapters,with the main results summarized as follows:Chapter 2.We have demonstrated a convenient method to fabricate the flexible microchannel,which possesses the excellent elastic property and dynamic stability with maintaining liquid flows during the stretching and releasing state.Meanwhile,the flexible microchannel can be directly assembled onto various substrates,including organic,inorganic,and metallic.In addition,the flexible microchannel exhibits excellent mechanical deformability upon stretching(967%)and compressing.Meanwhile,its sensitive deformability upon microforces,including both in longitude and lateral directions,shows great potential in the application for strain sensors and pressure sensors.Chapter 3.We have demonstrated functional liquid-based stretchable microfluidics.Optimizing the matching of elastomer materials and functional liquids,a highly stable liquid interface inside the microchannel is obtain.Dependent on the dynamic of liquid,the functional liquid-based microfluidics can be ultra-smooth and ultra-slippery,which may repel a variety of liquids and refill any defects quickly after being stretched.Hence,the dynamic functional liquid-based microfluidics exhibit high transparency and excellent resistance to protein and organic molecules adsorption,even at the stretching state.Meanwhile,its application in flexible tensile sensing can increase the detection range.Chapter 4.We have demonstrated the thermoresponsive liquid gating microchannel with antifouling behavior and positionally controlled release capability.The temperature responsive hydrogel can respond to the external temperature and dynamically release and absorb the gating liquid through a porous matrix to achieve a dynamic switching performance.Meanwhile,the stable gating liquid layer on the surfaces of the porous matrix endows the microchannel with exceptional antifouling and antiswelling characteristics.Benefit from the multifunctional advantages of the thermoresponsive liquid gating system,we believe it will bring new opportunities to smart microscale flow control,drug delivery,chemical synthesis,medical devices.Chapter 5.We have demonstrated a very gentle method to prepare the "Liquidlike" surface by covalent layer-by-layer self-assembly inner surface of the microfluidics.The "Liquid-like" surface is similar to the slippery properties of the liquid.Meanwhile,it exists a binding site the antibodies of circulating tumor cells.When modifying EpCAM,"Liquid-like" surface-based microfluidics not only possesses the efficient capture of circulating tumor cells but also greatly reduces non-specific adsorption of leukocytes.It will provide a reliable basis for individualized treatment.